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    Mix‐Max: A Content‐Aware Operator for Real‐Time Texture Transitions
    (© 2024 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd., 2024) Fournier, Romain; Sauvage, Basile; Alliez, Pierre; Wimmer, Michael
    Mixing textures is a basic and ubiquitous operation in data‐driven algorithms for real‐time texture generation and rendering. It is usually performed either by linear blending, or by cutting. We propose a new mixing operator which encompasses and extends both, creating more complex transitions that adapt to the texture's contents. Our mixing operator takes as input two or more textures along with two or more priority maps, which encode how the texture patterns should interact. The resulting mixed texture is defined pixel‐wise by selecting the maximum of both priorities. We show that it integrates smoothly into two widespread applications: transition between two different textures, and texture synthesis that mixes pieces of the same texture. We provide constant‐time and parallel evaluation of the resulting mix over square footprints of MIP‐maps, making our operator suitable for real‐time rendering. We also develop a micro‐priority model, inspired by micro‐geometry models in rendering, which represents sub‐pixel priorities by a statistical distribution, and which allows for tuning between sharp cuts and smooth blend.
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    Htex: Per-Halfedge Texturing for Arbitrary Mesh Topologies
    (ACM Association for Computing Machinery, 2022) Barbier, Wilhem; Dupuy, Jonathan; Josef Spjut; Marc Stamminger; Victor Zordan
    We introduce per-halfedge texturing (Htex) a GPU-friendly method for texturing arbitrary polygon-meshes without an explicit parameterization. Htex builds upon the insight that halfedges encode an intrinsic triangulation for polygon meshes, where each halfedge spans a unique triangle with direct adjacency information. Rather than storing a separate texture per face of the input mesh as is done by previous parameterization-free texturing methods, Htex stores a square texture for each halfedge and its twin.We show that this simple change from face to halfedge induces two important properties for high performance parameterization-free texturing. First, Htex natively supports arbitrary polygons without requiring dedicated code for, e.g, non-quad faces. Second, Htex leads to a straightforward and efficient GPU implementation that uses only three texture-fetches per halfedge to produce continuous texturing across the entire mesh. We demonstrate the effectiveness of Htex by rendering production assets in real time.
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    PROOF: An Architecture for Rendering In Object Space
    (The Eurographics Association, 1988) Schneider, Bengt-Olaf; Claussen, Ute; A. A. M.Kuijk
    This paper gives a short introduction into the field of computer image generation in hardware. It discusses the two main approaches, namely partitioning in Image space and In object space. Based on the object space partitioning approach we have defined the PROOF architecture. PROOF is a system that aims at high performance and high quality rendering of raster images. high performance means that up to 30 pictures are generated in one second. The pictures are shaded and anti-allased, giving the images a high degree of realism. The architecture comprises tnree stages which are responsible for hidden surface removal, shading, and filtering respectively. The first of these stages a pipeline of object processors. Each of these processors stores and scan converts one obiect Furthermore, It interpolates the depth and the normal vector across the Object. Each object processor IS able to handle objects of a certain primitive type. The specialization of an object processor to a certain primitive type is encapsulated in a Single block called primitive processor. The Outout of the object processor pipeline is the input to a stage for shading. The illumination model employed takes In~o account both diffuse and specular reflections. The paper reviews Gouraud and Phong shading with regard to their suitability for a hardware implementation. The final stage of the PROOF system is formed by a stage for filtering the colours of those objects that contribute to a pixel. This done by constructing a subpixel mask and filtering across an area of 2x2 pixels. At the end. the paper briefly reports on the current state of the project.
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    VLSI Architecture for Anti-Aliasing
    (The Eurographics Association, 1989) Romanova, Claudia; Wagner, Ulrich; Richard Grimsdale and Wolfgang Strasser
    Computer-synthesized images exhibit the typical artifacts of raster displays, called alias­ ing, rastering, staircasing or the "jaggies". Display of an image on a raster CRT requires the sampling the two dimensional image signal I( x, y) to obtain a pixel-based description of intensity. Unfortinately, this sampling process treates the pixel as a mathematical point and the point sampling of an unfiltered object is never correct at any resolution. Aliasing effects (spatial and temporal) are due to undersampling of the image signal. Spatial aliasing occurs when images contain frequencies greater than one half the spa­ tial sampling frequency. Lines that should be straight appear jagged, very small objects may not be visible, portions of long thin objects may disappear.